I feel like I've been seeing a lot of comments lately to the effect of, "no - that would be illegal!" Yeah, we are talking about criminals who are already breaking one law. Often criminals who, in the very nature of their crime, are hard to identify.

But then, even if they're not overtly breaking the law with a simple request for information, debt collectors and car warranty salesman are notorious for sending letters that will imply they are your financial institution, the letter was sent by your account manager, etc. IRS impersonators will tell people that jail time is imminent. I can imagine someone could create something that looks to a non-lawyer (who's afraid and not paying attention) like it's basically warrant signed by someone who's basically a judge, but just doesn't outright say that. You'd still need to verify - hey is this person actually a judge, and did this person actually sign that as a warrant?